WASHINGTON — The immediate impact of President Obama’s health-care laws wasn’t on sick kids or the uninsured — but on big-time employers whacked by a costly new tax on drug benefits for retirees.

Farm-equipment giant John Deere yesterday said the tax will trigger a one-time loss of $150 million, rival Caterpillar reported a $100 million hit and Valero Energy will take a $15 million loss.

Steel-giant AK Steele Holding Corp. said it will charge off $31 million.

Analysts say up to 2 million people could lose prescription-drug coverage provided by former employers, forcing them onto Medicare rolls.

“It’s a big deal,” an executive at New York-based Verizon told The Post. “It will impact retirees and on what kind of future benefits are offered.”

The exec said his company had about 200,000 retirees with prescription-drug coverage, which will cost Verizon about $46.6 million a year in new taxes — resulting in a one-time reduction of forecast earnings of about $500 million.

About 1,500 large companies will be hit by the tax and drop $14 billion in profits, according to estimates by benefits consultants Towers Watson.

The tax applies to federal subsidies paid to companies that provide drug benefits to retirees who otherwise would be on the Medicare Part D drug plan.

The previous exclusion of a tax was created with the Part D plan to encourage employers to continue drug coverage, saving Medicare dollars.

The average subsidy is about $665 per retiree. Now it will be subject to a roughly 35 percent corporate tax — about $233 for each retiree per year.

The White House hopes to raise $5 billion over 10 years from the new tax to help pay for the health overhaul that expands coverage to 32 million Americans.

But it may cost in the long run, critics say, as businesses opt out of retirement plans or cut hiring.

The final touches were put on the bill yesterday as the Senate voted 56-43 to make some changes, while the House added its approval by 220-207. President Obama is expected to sign the final bill next week.